//=============================================================================
// System  : MatchKit
// File    : InternalRepeaterPattern.cs
// Author  : Fabio Bussu  (matchkit@fabiobussu.it)
// Updated : 04/16/2013
// Note    : Copyright 2013, Fabio Bussu, All rights reserved
//
// This code is published under the Microsoft Public License (Ms-PL). A copy
// of the license should be distributed with the code.  It can also be found
// at the project website: http://matchkit.codeplex.com. This notice, the
// author's name, and all copyright notices must remain intact in all
// applications, documentation, and source files.
//
// Version     Date     Who  Comments
// ============================================================================
// 1.0.0.0  04/16/2013   FB  First draft
//=============================================================================
using System;
using System.Collections.Generic;
using System.Runtime.Serialization;
using MatchKit.Patterns;

namespace MatchKit.ObjectMapping.Patterns
{
	#if DC
	[DataContract]
	#endif
	#if SZ
	[Serializable]
	#endif
	sealed class InternalRepeaterPattern : BasePattern
	{
		#if DC
		[DataMember]
		#endif
		private IPattern _item;

		public InternalRepeaterPattern(IPattern item)
		{
			if (item == null)
				throw new ArgumentNullException("item", "item cannot be null");
			_item = item;
		}

		public override IEnumerable<IPattern> Children
		{
			get { yield return _item; }
		}

		public override bool HasChildren
		{
			get { return true; }
		}

		protected override Match OnMatch(MatchContext context)
		{
			var items = new List<Match>();
			var values = new List<object>();
			#region tracer
			var tracer = context.Tracer;
			int repeatNo = 0;
			#endregion

			while (!context.IsEos)
			{
				#region tracer
				if (tracer != null)
				{
					IMatchTracerExtensions.BeginMatch(tracer, context, _item, "Repeat #{0}", ++repeatNo);
				}
				#endregion

				var branch = context.Branch();
				var m = _item.Match(branch);
				var objectMatch = m as ObjectMatchInfo;

				#region tracer
				if (tracer != null)
				{
					IMatchTracerExtensions.MatchComplete(tracer, context, m, "End repeat #{0}", repeatNo);
				}
				#endregion

				if (!m.Success)
				{
					// se ho fatto match di almeno un elemento considero successo
					if (values.Count != 0)
						break;

					return m;
				}

				context.Commit(branch);
				items.Add(m);
				values.Add(m.Value);

				// se l'elemento che garantisce continuita' all'array non era presente, esco dal ciclo
				if (objectMatch != null 
					&& objectMatch.HasRepeatingElement 
					&& !objectMatch.RepeatableMemberMatched)
					break;
			}

			return Success(context, values.Count != 0 ? values.ToArray() : null, items.ToArray());
		}

		public override string HelpString
		{
			get { return "Repeatable " + _item.HelpString; }
		}
	}
}
